In 1921 the local DAR chapter had a boulder set atop Spirit Mound with a bronze plaque marking the Lewis and Clark site for posterity. Virgil McDonald, a resident of the farmhouse that stood on the northeastern slope, hauled the two ton monument to the summit with a team of horses. It remained there unmolested for eighty years, until the plaque was stolen in 2001. The National Park Service duplicated the plaque and the monument was moved to this location in 2004.